Method for performing cell switching or reselection in mbs service

Abstract

The application provides a method for cell switching or reselection selection in an MBS service, the method for cell switching or reselection is executed at a user equipment side, and the method comprises the following steps: obtaining a user service description, wherein the user service description comprises a temporary mobile group identifier, an MBS session service, and a first service area identifier of a current cell, the first service area identifier corresponds to the temporary mobile group identifier and the session service; receiving a system information block of a broadcast control channel, wherein the system information block comprises second service area identifiers of a plurality of neighboring cells; and selecting a corresponding neighboring cell containing the first service area identifier for cell switching or reselection in the second service area identifiers. Through the method for cell switching or reselection selection based on cell priority, the UE can continuously receive the MBS service.

Description

TECHNICAL FIELD

[0001] The disclosed embodiments of the present application relate to the field of MBS communication technology, and more particularly, to a method for cell switching or reselection in MBS service and a user equipment. BACKGROUND

[0002] The transmission mode of Multimedia Broadcast Multicast Service (MBMS) of LTE can be divided into SC-PTM (Single Cell Point-To-Multipoint) and MBSFN (Multicast-Broadcast Single Frequency Network). UE receives MBMS service through the transmission mode of SC-PTM, and when cell selection or cell reselection is needed, UE proceeds in the following way to ensure that MBMS service is not interrupted: ① receiving broadcast control channel SIB15, SIB15 contains SAI (MBMS Service Area Identities) of the cell and neighboring cells, if UE finds that the neighboring cell does not have the SAI it needs, when UE is in idle state and performs cell reselection, it may prefer to select the cell corresponding to the MBMS service it is interested in. When UE is in connected state and performs handover, it may send a notification to the target handover cell to establish MBMS service in advance so that the service is not interrupted. ② For each MBMS service supported by the cell, SC-MCCH (Single Cell MBMS Control Channel) will inform UE which neighboring cells can also support the same MBMS service, so that if UE performs cell switching or reselection to a cell that does not support these MBMS services, it can request to continue transmitting MBMS service through unicast. ③ UE in connected state can also notify the network side of the MBMS service it is interested in, so that the network side sets in advance to meet the mobility requirements of the broadcast multicast service and unicast service of UE.

[0003] But in the current MBS (Multicast Broadcast Service) in the 5G new air interface network, it does not involve the MBSFN transmission mode of the MBMS in the LTE network, but there are PTM (Point to Multipoint) and PTP (Point to Point) two transmission modes. And the MBS service needs to support the V2X service with high requirements for delay and reliability. Due to the difference in transmission mode and supported service, the method of UE cell switching or cell reselection in MBS service in NR network may also be different.

[0004] Therefore, it is necessary to propose a standard to define the method of UE cell switching or cell reselection in MBS service. SUMMARY

[0005] According to the embodiments of the present application, the present application proposes a method of cell switching or reselection in MBS service to solve the above technical problems.

[0006] According to the first aspect of the present application, a method of cell switching or reselection in MBS service is provided, which is executed at the user equipment side, and the method comprises: obtaining a user service description, the user service description comprising a temporary mobile group identifier, an MBS session service and a first service area identifier of the current cell, the first service area identifier corresponding to the temporary mobile group identifier and the session service; receiving a system information block containing second service area identifiers of a plurality of neighboring cells, and reading the second service area identifiers of the plurality of neighboring cells; selecting a corresponding neighboring cell containing the first service area identifier in the second service area identifier to switch to or reselect to.

[0007] According to the second aspect of the present application, a user equipment is provided, which comprises a processor and a communication circuit, the processor being connected to the communication circuit, and the processor being configured to execute the method of the first aspect.

[0008] According to the third aspect of the present application, a user equipment is provided, which stores instructions, and the instructions are executed to realize the method of the first aspect.

[0009] The beneficial effects of the present application are: the present application acquires a user service description through a UE, the user service description includes a temporary mobile group identifier, MBS session service and a first service area identifier of the present cell, so that the first service area identifier and the temporary mobile group identifier corresponding to the required MBS service of the UE can be known; and then the UE receives a system information block containing second service area identifiers of multiple neighboring cells, selects a corresponding neighboring cell containing the first service area identifier in the second service area identifier to switch to or reselect to, so as to continue to receive the required MBS service, thereby ensuring uninterrupted transmission of the required MBS service of the UE. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0011] Figure 1 is a schematic diagram of information elements of system information block 15 in MBMS;

[0012] Figure 2 is a flowchart of a cell switching or reselection method embodiment of the present application;

[0013] Figure 3 is a structural schematic diagram of a user equipment based on the cell switching or reselection method embodiment of the present application;

[0014] Figure 4 is a storage schematic diagram of a user equipment based on the cell switching or reselection method embodiment of the present application. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0016] In the conventional SC-PTM transmission mode of the MBMS service, a user service description (USD) includes a temporary mobile group identity (TMGI), a service session, a frequency point (F) and service area identities (SAI), i.e., USD = TMGI + session + F (frequency point) + SAI, which means that the MBMS service carried on the same frequency point is the same, i.e., the frequency point and the TMGI are corresponding, while the same frequency point can correspond to multiple SAIs, and there are at most 64 SAIs on the frequency band where the frequency point is located.

[0017] In the MBMS service, the UE performs cell switching or reselection based on the frequency priority to ensure continuous transmission of the service. The specific procedure is as follows: the UE obtains the USD at the application layer, based on which the UE can obtain the SAI corresponding frequency F and the TMGI of the MBMS service. The UE receives the SIB15 (System Information Block Type 15) sent by the broadcast control channel, and the information elements of the SIB15 are as shown in Table 2. Figure 1 The information element mbms-SAI-IntraFreq-r11 carries the frequency of the MBMS service of the current cell and the corresponding SAI, and the information element mbms-SAI-InterFreqList-r11 carries other frequency of the MBMS service of the neighboring cell and the corresponding SAI. When performing cell reselection or switching or reselection, the UE can preferentially select the cell of the required MBMS service.

[0018] Specifically, the following example can be used for illustration. For example, the UE obtains the USD through the application layer, and the content in the USD is as shown in Table 1.

[0019] Table 1

[0020] [Table 0001]

[0021] SAI carrier frequency point TMGI session service 1 F1 TMGI1 Session1 2 F1 TMGI1 Session2 3 F1 TMGI2 Session1 … … … … 63 F1 TMGI62 Session1 64 F1 TMGI63 Session1 65 F2 TMGI65 Session1

[0022] [Table 0002]

[0023] 66 F2 TMGI66 Session1

[0024] From Table 1, it can be known that F1 in the USD contains 64 SAIs, which correspond to 63 TMGIs and 64 sessions, and F2 contains 2 SAIs, which correspond to 2 TMGIs and 2 sessions.

[0025] The UE acquires the SAI of the five neighbor cells through receiving the SIB15 of the broadcast control channel, and the details are shown in Table 2.

[0026] Table 2

[0027] [Table 0003]

[0028]

[0029]

[0030] Suppose that the UE is interested in the service of TMGI2 (corresponding to SAI = 3), and through Table 1, it is known that the service is carried on the carrier frequency point F1, then when the UE performs cell reselection or cell switching, it will preferentially search for the corresponding cell according to the carrier frequency point F1 in the neighbor cell, and will not consider whether other frequency points such as F2 of the neighbor cell carry the service. Further, by searching for the cell 1, the cell 2 and the cell 3 all contain the carrier frequency point F1, and then according to the SAI of the service being 3, it is provided only in the cell 1 and the cell 2, so the UE will select in the cell 1 and the cell 2, and will not select the cell 3.

[0031] Of course, in an embodiment, when the TMGI and the carrier frequency point of the MBS service are bound to correspond, the MBS service can also use the above-mentioned frequency priority-based cell switching or reselection method to ensure the continuous transmission of the MBS service. But in the existing new radio network, the TMGI and the carrier frequency point F may not be bound to correspond, and different carrier frequency points may carry the same MBS session service.

[0032] In another embodiment, the present application provides a method for performing cell switching or reselection in an MBS service, which is performed at the UE side, and the method is based on cell priority to perform cell switching or reselection to ensure the continuous transmission of the MBS service, please refer to Figure 2 , Figure 2 is a flowchart of an embodiment of the cell switching or reselection method of the present application, and specifically includes the following steps:

[0033] S110: Acquire user service description, the user service description includes temporary mobile group identifier, MBS session service and first service area identifier of the cell, the first service area identifier corresponds to the temporary mobile group identifier and the session service.

[0034] In order to receive the MBS service on the MBS service control channel, the UE usually completes a service announcement process, in which the USD is received, wherein the UE can obtain the USD information in a broadcast manner, or obtain the USD information of the MBS service in a non-broadcast manner (such as unicast, Email, etc.), and the application does not limit the manner in which the UE obtains the USD information. The USD information usually includes a first service area identifier (SAI) of the MBS service of interest to the UE, a temporary mobile group identifier (TMGI), and an MBS session service (session). In the embodiment, the first SAI further includes a mobile country code (MCC), a mobile network code (MNC), a location area code (LAC), and a service area code (SAC). The TMGI includes the MCC, the MNC, and the MBS service ID. The MBS session further includes a start time (start) of the MBS service, a service duration (duration), and the like. Therefore, in one USD, the first SAI and the TMGI and the session correspond, and after the UE reads the USD, the UE can know which TMGI (i.e., which MBS service) the first SAI corresponds to.

[0035] S120: receiving a system information block of a broadcast control channel, the system information block containing a plurality of second service area identifiers of a plurality of neighboring cells.

[0036] The UE can receive a system information block through the broadcast control channel, wherein the system information block includes a plurality of second SAIs of the MBS services of the plurality of neighboring cells continuously transmitted in the current period, and the number of the second SAIs can be multiple. The UE can know whether there is an SAI of interest in the second SAIs by reading the plurality of second SAIs of the plurality of neighboring cells.

[0037] S130: selecting to switch to or reselect to a corresponding neighboring cell containing the first service area identifier in the second service area identifier.

[0038] The session service of the TMGI corresponding to the first SAI is of interest to the UE, and the UE can select to switch to or reselect to the cell by comparing whether the first SAI exists in the plurality of second SAIs of the plurality of neighboring cells. Of course, the second SAI also includes a mobile country code (MCC), a mobile network code (MNC), a location area code (LAC), and a service area code (SAC).

[0039] Specifically, the above embodiment is continued to be exemplified. For example, the UE obtains the USD, and the content in the USD is as shown in Table 3.

[0040] Table 3

[0041] [Table 0004]

[0042]

[0043]

[0044] [Table 0005]

[0045] 65 TMGI65 Session1 66 TMGI66 Session1

[0046] From Table 3, it can be seen that in the USD, the SAI only corresponds to the TMGI and the session, and does not force to limit which carrier frequency point carries which TMGI of the MBS service. Assuming that the MBS service of interest to the UE is TMGI2, corresponding to SAI=3.

[0047] The UE obtains the SAI of the other 5 neighboring cells through receiving the system information block of the broadcast control channel, and Table 4 is shown as follows.

[0048] Table 4

[0049] [Table 0006]

[0050] SAI carrier frequency point neighboring cell code 3 F1 cell 1 65 F1 cell 2 5 F1 cell 3 3 F2 cell 4 66 F2 cell 5

[0051] The UE is interested in the MBS service of SAI=3, and it can be seen from Table 4 that both cell 1 and cell 4 can provide the service, and the UE will select the cell in cell 1 and cell 4, without considering whether the carrier frequency point F1 or the carrier frequency point F2 carries the service. It can be understood that in the method of selecting the cell based on the cell priority for cell switching or reselection, the carrier frequency point is not the primary selection condition, and the neighboring cell containing the SAI of interest is directly selected for switching or reselection based on the SAI.

[0052] As described above, when the corresponding neighboring cell containing the first SAI is selected for switching or reselection in the second SAI, the UE selects the final cell for switching or reselection according to the traditional cell selection method, the random selection method, or the method according to the implementation of the UE to switch or reselect to the target neighboring cell. When the connected UE switches to the target neighboring cell containing the first SAI, it will send a notification to establish the MBS service to the target neighboring cell to establish the MBS service in advance, so as to ensure uninterrupted transmission of the MBS service. When the UE in the inactive state or the idle state performs cell reselection, it will preferentially select the cell of interest as the target neighboring cell.

[0053] In another embodiment, the USD information can also include the carrier frequency point, and the same TMGI of the MBS service can be carried on the same carrier frequency point, or the same TMGI of the MBS service can be carried on different carrier frequency points. When the same MBS service is carried on different carrier frequency points, the first SAI can be set to be the same or different, and the SAI of the frequency band where the carrier frequency point is located is less than or equal to 64.

[0054] Specifically, the above examples can be continued to be explained. For example, the UE obtains the USD, and the content in the USD is shown in Table 5.

[0055] Table 5

[0056] [Table 0007]

[0057] SAI carrier frequency point TMGI session service 1 F1 TMGI1 Session1 2 F1 TMGI1 Session2 3 F1 TMGI2 Session1 … … … … 63 F1 TMGI62 Session1 64 F1 TMGI63 Session1 3 or 65 F2 TMGI2 Session1 66 F2 TMGI66 Session1 67 F3 TMGI67 Session1 68 F3 TMGI68 Session1

[0058] From Table 5, it can be known that the F1 in the USD contains 64 SAIs, which correspond to 63 TMGIs and 64 Sessions, and the F2 contains 2 SAIs, which correspond to 2 TMGIs and 2 Sessions. However, the MBS service of TMGI2 is also contained in the F2, and the corresponding SAI can be the same as that in the F1, that is, SAI=3, or can be different from that in the F1, that is, SAI=65. That is, when the same MBS service is carried in different carrier frequencies, the SAI can be set to be the same or different.

[0059] The UE obtains the SAIs of the other 6 neighboring cells by receiving the system information block of the broadcast control channel, and the details are shown in Table 6.

[0060] Table 6

[0061] [Table 0008]

[0062] SAI carrier frequency point neighboring cell code 3 F1 cell 1 64 F1 cell 2 5 F1 cell 3 3 F2 cell 4 66 F2 cell 5 67 F3 cell 6

[0063] Suppose the UE is interested in the TMGI2, from Table 5, it can be known that the corresponding first SAI is 3 or 65, and the carrier frequency carrying the MBS service is F1 or F2, so when the second SAI of the neighboring cell is obtained for cell switching or reselection, the cell containing the carrier frequency F1 or F2 will be considered first, and the cell containing the carrier frequency F3 will not be considered. From Table 5, it can be known that the UE will first consider the 5 cells containing F1 and F2 (cell 1, cell 2, cell 3, cell 4 and cell 5), and then find the cells containing the first SAI in the 5 cells, that is, cell 1 and cell 4, and the UE will select in the two cells, and of course the final target neighboring cell switching or reselection can be performed according to the traditional cell selection, random selection or according to the implementation of the UE. It can be understood that in the embodiment, the UE is based on the carrier frequency and the cell to consider the method of cell switching or reselection.

[0064] To sum up, in the MBS service in the NR network, the UE can perform cell switching or reselection based on frequency priority, can perform cell switching or reselection based on cell priority, and can perform cell switching or reselection based on frequency and cell simultaneously. Through the above-mentioned cell switching or reselection method, it is ensured that the UE can not interrupt receiving the MBS service when performing cell switching or reselection.

[0065] Referring to Figure 3 , Figure 3 is a structural schematic diagram of an embodiment of a user equipment of the present application. The user equipment 10 comprises a processor 12 and a communication circuit 11; the processor 12 is connected to the communication circuit 11, and the processor 12 is used to execute instructions to realize the above-mentioned cell switching or reselection method.

[0066] The processor 12 can also be referred to as a CPU (Central Processing Unit). The processor 12 can be an integrated circuit chip with signal processing capability. The processor 12 can also be a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application-Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor 12 can also be any conventional processor.

[0067] Referring to Figure 4 , Figure 4 is a storage structure schematic diagram of the user equipment in the embodiment of the present application. The user equipment 20 of the embodiment of the present application stores instruction / program data 21, which is executed to realize the method provided by any embodiment and any non-conflicting combination of the cell switching or reselection method of the present application. Wherein, the instruction / program data 21 can form a program file and be stored in the storage medium of the above-mentioned user equipment 20 in the form of a software product, so as to make a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor execute all or part of the steps of the method of each embodiment of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a ROM (Read-Only Memory), a RAM (Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes, or a computer, a server, a mobile phone, a tablet, and other terminal devices.

[0068] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the division of the units is only a logical function division, and there can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0069] In addition, each function unit in the various embodiments of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit. The integrated unit can be implemented in the form of hardware, or in the form of a software function unit.

[0070] The above is only an implementation manner of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for cell handover or reselection in an MBS service, characterized in that, The method is executed at a user equipment side, and the method comprises: obtaining a user service description, the user service description comprising a temporary mobile group identity, an MBS session service, and a first service area identity of a current cell, wherein the first service area identity corresponds to the temporary mobile group identity and the session service; receiving a system information block of a broadcast control channel, the system information block containing second service area identities of multiple neighboring cells; selecting, in the second service area identities, a corresponding neighboring cell containing the first service area identity to switch to or to reselect to; wherein the MBS session service is carried on different carrier frequencies, the first service area identity is set differently on the different carrier frequencies, and when the MBS session service is carried across multiple carrier frequencies, the user equipment selects, based on the first service area identity, a neighboring cell supporting the MBS session service to switch to or to reselect to.

2. The method of claim 1, wherein, The first service area identity and the second service area identity comprise a mobile country code, a mobile network code, a location area code, and a service area code.

3. The method of claim 1, wherein, The selecting, in the second service area identities, a corresponding neighboring cell containing the first service area identity to switch to or to reselect to further comprises: selecting, according to the MBS session service, a corresponding carrier frequency carrying the MBS session service in the second service area identities; selecting, according to the carrier frequency, a corresponding neighboring cell containing the first service area identity to switch to or to reselect to.

4. The method of claim 1, wherein, The carrier frequency is located in a frequency band containing less than or equal to 64 service area identities.

5. The method of claim 1, wherein, The selecting, in the second service area identities, a corresponding neighboring cell containing the first service area identity to switch to or to reselect to further comprises: when the corresponding neighboring cell containing the first service area identity is multiple, the UE switches to or reselects to a target neighboring cell according to a conventional cell selection method, a random selection method, or a UE implementation method.

6. The method of claim 5, wherein, The switching to the target neighboring cell further comprises: the UE in a connected state switches to the target neighboring cell and sends a notification of establishing an MBS service to the target neighboring cell to establish the MBS service in advance.

7. A user equipment, comprising: comprising a processor and a communication circuit, the processor being connected to the communication circuit; the processor is configured to execute the method in any one of claims 1-6.

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